Privacy in Relationships

How much privacy should people have in Relationships? my boyfriend and I been together for 6 months and known eachother for a year before that. When we first started dating again I used to go through his phone and would always find stuff that I deem as inappropriate and most of the time he would agree and adjust his actions. Now it's to the point that he doesn't agree with some things that I feel are inappropriate or disrespectful (social media content). Also, he feels that he should have more privacy and changed his passwords on his phone and social medias. Thoughts ladies?